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PHP Exercises: Check if the value of each element is equal or greater than the value of previous element of a given array of integers

PHP Basic Algorithm: Exercise-130 with Solution

Write a PHP program to check if the value of each element is equal or greater than the value of previous element of a given array of integers.

Sample Solution:

PHP Code :

<?php
function test($numbers)
    { 
       for ($i = 0; $i < sizeof($numbers) - 1; $i++)
          {
             if ($numbers[$i + 1] < $numbers[$i]) 
             return false;
          }
        return true;
    }  
    
var_dump(test([5, 5, 1, 5, 5]));
var_dump(test([1, 2, 3, 4]));
var_dump(test([3, 3, 5, 5, 5, 5]));
var_dump(test([1, 5, 5, 7, 8, 10]));

Sample Output:

bool(false)
bool(true)
bool(true)
bool(true)

Flowchart:

Flowchart: Check if the value of each element is equal or greater than the value of previous element of a given array of integers.

PHP Code Editor:

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Previous: Write a PHP program to create new array from a given array of integers shifting all even numbers before all odd numbers.
Next: Write a PHP program to check a given array (length will be atleast 2) of integers and return true if there are two values 15, 15 next to each other.

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PHP: Tips of the Day

$GLOBALS: An associative array containing references to all variables which are currently defined in the global scope of the script. The variable names are the keys of the array

Example:

<?php
$myGlobal = "global"; // declare variable outside of scope
function test()
{
$myLocal = "local"; // declare variable inside of scope
 // both variables are printed
 var_dump($myLocal);
 var_dump($GLOBALS["myGlobal"]);
}
test(); // run function
// only $myGlobal is printed since $myLocal is not globally scoped
 
var_dump($myLocal);
var_dump($myGlobal); 
?>

Output:

string(5) "local"
string(6) "global"
NULL
string(6) "global"

In the above example $myLocal is not displayed the second time because it is declared inside the test() function and then destroyed after the function is closed.

Becoming global

To remedy this there are two options.

Option one: global keyword

function test()
{
 global $myLocal;
 $myLocal = "local";
 var_dump($myLocal);
 var_dump($GLOBALS["myGlobal"]);
}

The global keyword is a prefix on a variable that forces it to be part of the global scope.

Note that you cannot assign a value to a variable in the same statement as the global keyword. Hence, why I had to assign a value underneath. (It is possible if you remove new lines and spaces but I don't think it is neat. global $myLocal; $myLocal = "local").

Option two: $GLOBALS array

function test()
{
 $GLOBALS["myLocal"] = "local";
 $myLocal = $GLOBALS["myLocal"];
 var_dump($myLocal);
 var_dump($GLOBALS["myGlobal"]);
}

In this example I reassigned $myLocal the value of $GLOBAL["myLocal"] since I find it easier writing a variable name rather than the associative array.